ML20247L180
| ML20247L180 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 05/16/1989 |
| From: | Helwig D PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-65871, NUDOCS 8906020102 | |
| Download: ML20247L180 (4) | |
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.PHILADE'LPHIA ELECTRIC COMPANY '
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P.CL BOX 8699 PHILADELPHIA A, PA.19101 (215)841 4000 -
May'16, 1989
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Docket Nos.'50-277 50-278 TAC No. 65871 U.S.. Nuclear Regulatory ~ Commission
-Attn: Document' Control Desk
- Washington, DC 20555'
SUBJECT:
.In-House' Reload Licensing for Peach Bottom Atomic Power Station Units 2 and 3
REFERENCE:
April 10,-198911etter-from R. E. Martin (NRC) to G. A. Hunger, Jr. (PECo)
Dear Sir:
. 1 L
Enclosed is the additional information requested by the referenced NRC letter pertaining to PECo report PECo-FMS-003,
" Steady State Fuel' Performance Methods Report."
If you have any questions or require additional information, please'do'not: hesitate to contact us.
L Very trul
- yours, D.
R.- Helwig Acting General Manager Nuclear Services Enclosure cc:
W.
T.
Russell, Administrator, Region I, USNRC T.,P.
Johnson, USNRC Senior Resident Inspector
'J.
Urban,:Delmarva Power
-J.
T.
Boettger, Public~ Service Electric & Gas AUDI i
H.
C.
Schwemm, Atlantic Electric T. ;M. Gerusky, Commonwealth of Pennsylvania l
r.
8906020102 890516 ADOCK0500gg{7 PDR P
l 1
e-Rosponce to Requsst.for Additional Docket Nos. 50-277 i
Information on PECo-FMS-003
'50-278 Page 1 of 3 NRC Request In order for this code to be used for gadolinia rod analysis, 1
PECo.must submit the following:
1)
The'gadolinia material properties used in the code,
- 2)
How gadolinia rod powers are determined as a function of burnup (including the radial power distribution in the gadolinia pellet) for the specific analyses to be performed, and-1 3)
The upper level of gadolinia concentrations.to be'used by j
PECo.
j l
An. example of.the UO -Gd 03 material properties 2
2 that need to be addressed are theoretical density, thermal f
expansion, thermal conductivity, specific heat, and melting temperature, etc.
I Responses
-1 1)
Gadolinia Properties:
3 The gadolinia material properties used by'FROSSTEY were obtained from the code developer, Yankee Atomic Electric Company.(YAEC).
The properties used are as'follows:
Theoretical Density:
FROSSTEY calculates the fuel rod theoretical density (TD) with the following equation:
TD
= (FRP)(11.46) +-(FRG)(7.407) + (FRU)(10.96)
Where:
initial weight fraction of the fuel pellet which FRP
=
is Puo2 (Input Value) initial weight fraction of the fuel pellet which FRG
=
is Gd 02 3 (Input Value)
FRU 1.0-FRP-FRG, which is the initial weight
=
fraction of the fuel pellet which is UO2 11.46 theoretical density of Pu02 in gm/cc
=
7.407 =
theoretical density of Gd 03 in gm/cc 2
10.96 theoretical density of UO2 in gm/cc
=
d
l Msy 3, 1989~
Page 2 of 3 Thermal Expansion-and Thermal Conductivity:
' FROSSTEY calculates the' thermal expansion and the thermal conductivity,of the fuel. pellet utilizing equations 1
developed by General Electric (GE) and incorporated into the code'by YAEC.
These equations have been previously approved by NRC for GE's use in. Loss of Coolant Accident analyses l
models.
The. thermal expansion and thermal conductivity equations were included in GE proprietary information provided to NRC in support of.the submittal as defined in i
the Licensing Topical Report NEDO - 23785-1-A, GESTR-LOCA model. 'Since these equations are GE proprietary information and they have been previously approved by NRC, the equations are not included but are referenced as. agreed upon during~
the telephone conversation between PECo' staff, NRC staff and the NRC-staff's. consultant on December 9, 1988.
Specific Heat:
FROSSTEY uses the specific heat correlation of J. F. Kerrisk and P.'G. Clifton - Smoothed Values of the Enthal Capacity of UO ", Nuclear Technology, Volume 16 (py-and Heat 2
1972).
- This correlation,is not a function of gadolinia.
The specific heat does not appear in the FROSSTEY steady state heat conduction equation and, thus, does not impact the prediction of gap conductivity or other parameters.
It is used to calculate fuel sensible heat for informational purposes only.
PECo does not use the calculated sensit'e heat'in reload design and licensing.
Melting Temperature:
FROSSTEY calculates the melting. temperature (TM) with the following equation:
TM
= Tmelt - 500(FRP + FRG)-32(Bu/10000)
Where:
I i
= The unadjusted melting) temperature ( C)
Taelt (Input value of 2790 C Initial weight fraction of the fuel material FRP
=
which is Puo2 (Input Value)
Initial weight fraction of the fuel material FRP
=
which is Gd 023 Local fuel burnup (mwd /MTM)
Bu
=
fl-a_1________.__..-----__
.May 3, 1989 Page 3 of 3 I
2)
Relative Rod. Powers and Radial Distribution:
PECo utilizes FROSSTEY in the calculation of core average-i and hot-channel gap conductivity for use in reload licensing transient analysis.
The following methods / assumptions are i
used with regard to relative UO2 and Gd 023 fuel rod power distribution when determining For the calculation of core average gap, gap conductivity. conductivity, power 6
is apportioned.to each fuel batch as. determined by the 3-D simulator.
Within each batch, the fuel rod duties (both l
2 and Gd 0 ) are. assumed to be distributed UO 23 evenly.
Thus, representative UO2 and Gd 0 ' fuel 23 rods are evaluated at the batch average power-(i.e. KW/ft).
'When determining the hot channel gap conductivity, it is
'4 conservatively assum.ed that every rod (U0g and:
Gd 0 ) is-operated at the MAPLHGR KW/ft limit for 23 the bundle lifetime.
The radial power distribution in the gadolinia fuel' pellets I
is assumed to be the same as that for UO2 fuel. pellets.
i 3)
Gadolinia Concentrations:
l The upper level of gadolinia concentration to be used by PECo is 5.0%.-
This is.within the bounds of the gadolinia material property correlations.
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